Electromagnetically controlled latch device



w 4 m 0 m M 3N w am M, Mm E 5 M m M a U w w W. S. ANDERSON, JR

ELECTROMAGNETICALLY CONTROLLED LATCH DEVICE Filed Aug. 23, 1948 Fig.

Sept. 9, 1952 known in the art.

Patented Sept. 9, 1952 ELECTROMAGNETICALLY CONTROLLED LATCH DEVICEWilliam S. Anderson, Jr., Williamsport, Pa., as-

signor of one-half to James Williamsport, Pa.

E. Axeman,

Application August 23, 1948, Serial No. 45,777

Claims.

This invention relates to electromagnetically controlled latch deviceswhich are interposed between electromagnetic devices and independentlymoved members in order to control the latter, and it has for its mainobject to provide a latch device of great simplicity, havingintermediate members which ar not positively connected or linked withthe said electromagnetic devices or independently moved members, butwhich nevertheless permit perfect control of the last named members atthe right moment without entailing any reaction on the electromagneticdevice.

Latching devices for the armatures or other movable elements ofelectromagnetic devices such as solenoids, relay switches, and the likeare well But such devices are complicated, requiring usually trip coilsor manually operable tripping means and are therefore unreliable inoperation. Moreover they do not always eliminate completely reaction ofthe movable elements onthe electromagnetic device and they free themovable member to be controlled immediately upon operation of theelectromagnetic device. These facts cause certain drawbacks ordisadvantages.

It is, for instance, repeatedly necessary to use electromagnetic devicesin installations in a home, where noisy operation is highlyobjectionable. Such noisy operation is however a necescesary consequenceof the operation of parts, such as above described, as the reaction ofmoved parts on 'a solenoid core for instance, holding the latter in aposition in which the magnetic forces are not capable of moving saidparts'into the position to which-they are attracted, causes a noisybuzzing and other sounds due to magnetically produced vibrations andalso excessive heating. Likewise a positive connection of anelectromagnetic device with an independently movable member whichoperates under the influence of gravity in certain moments, causes noisystriking of said member'against some stop or cooperating member. Furtherdisadvantages result from complexity and from the possibility of alocking or unlocking action at the wrong moment.

It is therefore an object of this invention to provide a latch mechanismfor the control of independently moving members, which may or may notmove under the influence of gravity, which eliminates the above defectsand which always allows the electromagnetically operated members to goto the home position in which no further movement will be set up,without any interference by those members which are controlled by saidelectromagnetic device.

It is a further object of the invention to provide a latch mechanismwhich consists solely of members moving under the influence of forcesassociated with them, but cooperating with the electro-magneticallyoperated members, which mechanism therefore does not require auxiliarycoils or apparatus.

It is a further object of the invention to provide a latch mechanismwhich frees the movement of a gravity influenced independently movablemember only when the latter is in a certain phase of its movement andwhich guarantees that no gravity influenced striking of other parts willtake place.

It is a further object of the invention to provide a latch mechanismwith members provided with or influenced by biasing means, imparting tothem the tendency to adopt a predetermined position, said memberscooperating with movable electromagnetically controlled members of anelectromagnetic device, likewise provided with biasing means, impartingto them the tendency to move towards and to press upon the first namedmembers of the latch mechanism.

It is a further object of the invention to provide a latch mechanismwith members provided with or influenced by biasing means, imparting tothem a tendency towards moving into a predetermined position,cooperating with electromagnetically controlled members, provided withbiasing means which are counteracted by electromagnetic action and whichoverbalance or overcome the biasing means of the first named memberswhen th said electromagnetically controlled members are not underelectromagnetic influence.

It is a further object of the invention to provide a latch mechanism,interposed between an electromagnetic control device and anindependently movable member, which comprises members provided orconnected with biasing means imparting to them the tendency to move intoan unlocking position in which they unlock the independently movablemember, and permit motion of the same, said electromagnetic controldevice including members, likewise provided with or influenced bybiasing means urging them towards the members of the latch mechanism,the biasing means of said last named member, if not countered byelectromagnetic action, overcomin the biasing means of the members ofthe latch mechanism and holding the latter in their looking position inwhich they look the independently movable member.

It is a further object of the invention to provide a pivoted spring orlatch, cooperating with a spring or by gravity influenced member of anelectromagnetic device, the latch being operated either by the influenceof its own spring or gravity and by the spring or gravity influencedmember of the electromagnetic device, pressing on it and overcoming theforce acting on it.

It is a further object of the invention to provide a pivoted gravityoperated weighted latch which is operated by a gravity influenced coreor armature member of an electromagnetic device, counterbalancing theweighted latch when the electromagnetic device is deenergized, butfreeing it when the device is energized, the gravity influenced movementof said latch being also controlled by the pressure of the controlledindependently influenced member.

It is a further object of the invention to pro vide a pivoted gravityoperated weighted latch for the control of a gravity operatedindependently movable member, which. is capable of adopting twopositions, said latch cooperating with an electromagnetic device havinga gravity influenced core or armature'one of the positions adopted bythe latch being a locking position for the independently movable memberand being produced by the counterbalancing of the weighted portion ofthe latch by the action exercised by the gravity operated .armature ofthe electromagnetic"device on one hand and by pressure exercised by theindependently movable member on the other hand, the release of the latchfrom both forces, such as electromagnetic attraction of the armature andthe removal of pressure exercisedby the independently movable member,occurring merely in a certain phase of operation, being necessary formoving the latch member into its inoperative or unlocking position.

Further more specific objects will be apparent from. the followingdetailed specification.

The invention is illustrated in the accompanying drawing, showing oneembodiment thereof by way of example. It is however tobe understood thatthe example shown is merely illustrative, and has been selected for thepurpose of explaining, the principle of the invention and the bestmodeof applying saidprinciple. Other modes of applying the principle ofthe invention will be either foreshadowed in the following specificationor will be obvious to experts skilled in this'art on the base of theexplanations given. Modifications of the example shown are therefore notnecessarily departures from the essence of the invention.

In the accompanying drawing:

Figure l is an elevational side view of the latch arrangement, the levercontrolledby the latch, and the solenoid controlling the latter.

Figure 2 is a sectional elevationalview of the solenoid and latcharrangement showing the solenoid in a positionof de-energizatibn;

Figures 3 and 4 are sectional elevational views similar to that inFigure 2' showing the solenoid in its position of energization and thelatch in two different positions.

Figure 5 is a diagram illustrating a mechanism which is operated by thelatch.

Figure 6 is a' fragmentary view of the upper portion of the latch,showing a modification.

The invention as above explained comprises latching means, which areoperated by, but not in positive engagement or'connection witha'solenoid or electromagnet, said latching means being capable ofcontrolling the movement of an independently movable member, forinstance-limiting its movement in one position and releasing the 4 saidmember for free movement in the other position. In this way two memberseach capable of performing independent movements and not directlyconnected with the solenoid or electromagnet are controlled by thelatter, in a way which is sufficiently indirect to permit asubstantially noiseless and smooth 'operation'of each part to thedesired extent, while the-control is sufiiciently intensive to preventany failure or accidental escape of the independently movable membersfrom the electromagnetic control.

In the figures it is assumed that a lever H] has to be controlled by alatch mechanism in such a way that its movement which is derived from anindependent source, not shown in Figure 1, would carry it from an upperposition Illa, indicated in dotted lines, to a position lBb, indicatedin dots and dashes. The function of the latch is to confine or limit themovement of the lever 59 in such a way that it should not be capable tomove downwardly beyond the position it (shown infull lines), or may onlyperform a limited stroke or oscillation in one position of the latchwhile being free to perform a full stroke of oscillation under its ownpower in the second position of the latch.

The latch I2 is of gooseneck shape and consists of a hp [4 and arm [5projecting at the two ends of a connecting portion I 6. At one end ofthe lip M a weight I? is attached, acting as a biasing means which hasthe tendency to cause a rotational movement of the latch in the. senseof the clock in Figures 2-4. The latch may rock around a pivot pin i8which is preferably secured to the projecting arm !5, at a point whichis located near the middle or connecting portion [6.

The pivot pin 18 is preferably held in the two cheek pieces l9, mountedon a support bracket 21 by means of screws 22. a

A supporting plate 9 carries the foot structure 23 of the solenoid 24.This foot structure may be screwed into the supporting plate as shown soasto be firmly secured thereon and a gasket 3i may or may not be used tosecure a firm seat. The foot member has a central bore 34 providingaccess to the central portion of the solenoid structure, generallyindicated ;by reference numeral 24. k r V The solenoid structure is of aconventional type, It comprises the coil 2%,a sleeve 28 holding the coiland also encircling the solenoid. core member 2 1 in its interior, abase plug 39 at the top of the sleeve in which the screw bolt-47 isheld; cylindricaljacket or mantle 32 enclosing the coil structure and aclosure plate 33;, closing saidjacket and held between-said foot membernewc e s.

Y Slidably arranged withinthe sleev e;;28g is the movable armature orcore- 35 made'of soft iron which carries a bolt or stem 3'6 projectingoutwardly through the-foot member whichcarries a collared head disk; Mlsecured t0 it. Between the collar of the disk eii and astepped portionof the ccntralbore 34, a coil spring 42 is-inserted which presses thedisk 40 outwardly. Under normal conditions in. which the solenoidisdeener giaed the core 35 and therefore-rest against the arm 15 of thelatch l2 V v 1,

in the supporting bracketffi; or cheek piece 9 a stop plate 45 is heldagainstwhich the-arm IE or latch l2 mayrest when. held by Some; externalmeans, such as the head diskdlli-onicore 35 or by lever).- .1,

The operation of the latch mechanismgwill b'e more clearly understoodwhen". some example 31S advancing material to be processed.

given illustrating a specific case of a moving lever [0. In Figure 5 acam 50 is shown, seated on a rotating shaft 52, the eccentric portion 5|of which lifts the lever III at each revolution for a short time. Thepositions of the lever I are illustrated which correspond tothepositions [0,

10a and lllb in Figure 1. It may be assumed that the end of the lever l0operated by the cam moves some further member such as a ratchet pawl 54engaging a ratchet wheel 55 of an intermittently operating mechanism,whose operation is made dependent on the solenoid. For instance, theratchet wheel may be the driving means of an automatic stoker or of someindustrial machine If the process is dependent on heat for instance, asuitable thermostatic switch may operate the solenoid. These examplesare merely given in order to attach some meaning to the movements oflever H! but it will be clearly understood that the nature of themechanism moved by lever ID or the method of moving lever ID or theconditions of the energization of the solenoid have no direct connectionwith the operation.

Let it now be assumed that the lever i0 is lifted to its uppermostposition Illa while the solenoid is deenergized. The latch I2 is thenheld by the weight of the core and the spring 42 forming in this casethe biasing means of the core member 35 in the position shown in Figure2 and when the lever 10 moves downwardly from its position Illa to theposition [0 the lip of the latch will prevent further movement and willimmobilize the lever [0, which can solely be moved upwardly at the nextpassage of the eccentric portion of the cam.

Let it now be assumed that the lever l8 rests on the latch [2 asindicated in Figure 3, and that the solenoid coil 26 is energized. Thecore of the solenoid then slides immediately into its home positionwithdrawing the head disk 40 from the .arm [5. The coil spring is'thereby compressed but is preferably not completely compressed so that acertain amount of elasticity or resiliency is still present. The latch12 in this case does not fall back as long as lever l0 rests on lip I4,as the pressure of the lever prevents the tilting of the latch. Howeverwhen the lever is again moved upwardly, for instance, by the passage ofthe eccentric portion of the cam, the latch is freed and tilts andassumes the position shown in Figure 4, its arm I being now movedagainst the head disk 40 under the influence of its biasing means, suchas the weight H. The lever [0 when moving downwardly is no longerarrested by the lip 14 of latch 12 and can move under the influence ofgravity for instance, while keeping its end or head pressed against thecam disk 5|. The latch remains in the position shown until the solenoidi deenergized, at which time the biasing means of the core consisting ofthe weight of the core and of the head 40 and the tension of the springoverbalance the biasing means of the latch and return the latter to itslooking or stroke limiting position.

It will be clear that instead of using gravity as a biasing means forthe latch or for the core other means may be used, such as springs, airor fluid pressure or the like. The latch especially is only providedwith a special overbalancing weight such as shown, where the pivot hasto be so arranged that a tendency to tilt in the desired directioncannot be imparted by proper selection of the fulcrum point. Instead ofa weight a spring 48, as shown in Figure 6, may be used.

Likewise, in order to secure a holding of the 6 latch by the pressure orthe position of the movable lever l0, several means may be used.The-plane in which the lever moves may for instance, pass close to thepivot so that the contactof the lever with the lip prevents movement.Likewise the shape and position of the lever and of the lip may beutilized for obtaining the holding of the lip. This is shown in Figures2, 3 and 4 where it is manifest that the latch [2 cannot be tilted whenthe lever 10 rests on or is close to the lip [4.

A further mean is shown in Figure 6 in which the lip HI is provided witha short finger or projection 55 preventing tilting of the latch as longas contact between said projection and the lever is made.

The described arrangement has many advantages of a mechanical nature asit operates without any mechanical connections between the controlledparts. One of the main advantages, which is diiiicult to obtain withsolenoid arrangements, consists in its practically noiseless operation,Solenoids in which the core is mechanically connected with the load andin which therefore the load offers a resistance are emitting a mostdisagreeable buzzing sound as long as the resistance is not completelyovercome and the core is not in the home position. Moreover the solenoidis excessively heated as lon as the core is in any position other thanhome position,

Another cause of such noise is the lever I0. If for instance the leverID has to be arrested in a position'no't coinciding with its endposition (which is frequently necessary) the subsequent energization ofthe solenoid causes the latch to withdraw and the lever then strikes thecam again with much force making a most objectionable noise. Howeverwith the present arrangement thelever It] holds the latch l2 itself andonly frees the latch when raised by the cam, and in this case the leverslides on the cam and goes down with the cam in permanent contact withthe same. The noise thus disappears.

The two main sources of noise connected with the energizing of thesolenoid thus are elimi nated.

The sole source of possible noise is therefore the dropping of therelatively light latch, which may easily be cushioned by a rubber pieceapplied on arm I5 and which in any case strikes against a stillresilient member which may yield.

Deenergizing of the solenoid does not cause any objectionableclattering.

It is thus seen that all sources of objectionable noise are eliminated,so that the latch mechanism is applicable to all apparatus operating ina home or oifice.

It is to be understood that unessential details may be changed withoutin any way affecting the invention.

Having described the invention, what is claimed as new is:

1. An electromagnetically controlled latching mechanism for controllingthe movement of an operating member comprising in combination, a magnethaving a fixed part and a movable part and including means for causingthe movable magnet part to be moved in a first direction when the magnetis energized and to be moved in a second or reverse direction when themagnet is deenergized, a movable latch for said operating member mountedadjacent to but not connected with said movable magnet part, the latchhaving a part thereof mounted in the path of movement of the movablemagnet part and having movement in the line of movement of the movablemagnet part so that the movable magnet part moves away from the saidlatch part when the magnet is energized and moves against the latch partto move the latch to latching position when the magnet'is deenergizedand means associated with the latch for moving the said latch parttoward the movable magnet part but with a, force less than the forceurging the movable magnet part in the reverse direction to operate thelatch.

2. An electromagnetically controlled latch mechanism for controlling themovementof an operating member comprising incombination, a magnet havinga fixed part and a movable part and including means for moving themovable part in a first direction When' the magnet is energized and in asecond or'reverse direction but with a smaller and constantly actingforce when the magnet is deenergized, a latch for said operating membermovably mounted adjacent to but not connected with the movable magnetpart and having a portion which is mounted to be movable in the samedirectional line as the movable-magnet part, said latch portion being'disposedin the path of movement of the movable magnet part in suchposition as to be moved thereby when the magnet moveslin the reversedirectionto carry the latch to latching position, and means constantlyurging the latch out of latching position and toward the movable magnetpart but with a force less than that exerted bythe'movabl'e magnet partwhen moving in the reverse direction to operate the latch.

3'; An electromagnetically controlled mechanism as set forth" in claim2, wherein said latch is made as a pivoted lever having one arm portionarranged transversely'of the directional line of movement of saidmovable part of the magnet and movable along said directional line to beacted upon and moved by said movable part of the magnet, and the latchlever having'a connected arm portion arranged to coact with saidoperating member.

4. An electromagnetically controlled latching mechanism, comprising incombination, anoperating member, means'associated with saidoperating'memb'erfor periodically moving it ina first or outwardlydirection and constantly urging it in 8 the return direction, a" latchfor'holding said oper'ating member near the end of its outward movementto prevent itsactuation except for a short movement beyond latchingposition, the latch-and operating member having interengaging partsholding them together when engaged, the latch also having asecond partwhich is movable in a given directional line-for latching andunlatching' the operating member, amagnet having alateh operating partwhich moves in said given directional line to move said second latchpart to move the latch into latching position when the magnet isdeenergized and which movesaway from the said second latch part when themagnet is energized and the latch is held in engagement with saidopera-ting member, and means constantly urging saidlatch out of latchingposition and toward said latch operating part to cause the latch to bemoved out of latching position when released from said operating memberat the outer end of its movement in the first direction if the latch isnot held in latching position by the latch operating part of the magnetat this time.

5. Latching mechanism as set forthin claim 4, further characterized bythe fact that said latch is formed as a pivoted lever having one armportion cooperating with said magnet controlled latch operating part andone arm portion cooperating with said operating member;

S. ANDERSON, JR.

REFERENCES- CITEI) The following. references are of record in the fileof this patent:

UNITED STATES PATENTS Number Name Date 830,209 Conk-linget-al. Sept. 4,1906 869,014 Obester Oct. 22, 1907 883,029 King Mar. 24, 1908 978,857Day Dec. 20, 1910 1,144,033 Jacobs June 22, 1918 2,120,555 Good June'li,1938 2,262,061 Somers- Nov. 11, I941 FOREIGN PATENTS Number Country Date289,022 Germany Dec. 2, 1915

